Trouble logging in?If you can't remember your password or are having trouble logging in, you will have to reset your password. If you have trouble resetting your password (for example, if you lost access to the original email address), please do not start posting with a new account, as this is against the forum rules. If you create a temporary account, please contact us right away via Forum Support, and send us any information you can about your original account, such as the account name and any email address that may have been associated with it.

There's also the case of Kumokawa Seria : she seemed to know Touma, even before his memory loss (including his Imagine Breaker, and all his action since the first volume (thanks to her intelligence or her relation with the board of directors)).
Moreover, she was depressed when she heard that Touma died during WW3... so maybe they more than just "friends", if you know what I mean.

Even though Misaki knew Kamijou
The little interaction she had with Touma in that chapter gave us no solid proof of her connection to him (aside from trolling with Misaka)... and in V1 of the LN Touma, pre-memory lost, did mention her in a way or two but it looks like more of he knew her ability but not really the ability user...
And Touma is rather infamous after defeating Accelerator...
Though it would be nice if the two had some unknown past like that of Kumokawa...